Finance a new property w/2nd mortgage on existing rental?

[Brett Malen]

Hi BP community, wanted to collect your thoughts and idea's to help me brainstorm hacking some finances. Was thinking about taking a 2nd mortgage on an existing rental property to cover the costs of acquiring an additional property. Looking mostly for lessons learned or "wish I knew that beforehand" kind of advice.  Also, if you know of any lenders who give favorable (or better than standard) terms to investors under this scenario. Would be happy to hear some options. 

1st mortgage is covered and there is wiggle room for additional debt comfortably.